The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
An oxygen sensor may be positioned in an exhaust system of an engine. The oxygen sensor may generate an oxygen signal indicating oxygen levels in exhaust gas from the engine. The oxygen signal may also indicate an air/fuel ratio of the engine, which may be referred to as an actual air/fuel ratio. The amount of air and fuel provided to cylinders of the engine may be controlled based on a desired air/fuel ratio, such as a stoichiometric air/fuel ratio, and/or the actual air/fuel ratio.
Fuel control systems may operate in a closed-loop state or an open-loop state. In the closed-loop state, fuel delivery may be controlled to minimize differences between the desired air/fuel ratio and the actual air/fuel ratio. In the open-loop state, fuel delivery may be controlled independent from the actual air/fuel ratio. For example, fuel delivery may be controlled based on a fuel map.